Throttle controlling mechanism



R. s. SANFORD 2,148,305

Filed Sept. 4, 1956 2 Sheets-Sheet 1 Y THROTTLE CONTROLLING MECHANISM R.. m \m on 0 m a w. 2: s A N@ mam N U S c w y v B Q @w W a m@ a N E m0 mm NV Q0 @n mm mm QQW mfimmfiwvm. Q Q 322; MM QN 8 NM: 8 Wm mmwm. Q g N. NN a N Feb. 21, 1939.

7f A'TTORNEY Feb. 21, 1939; R, s. SANFORD 2,148,305

I THROTTLE CONTROLLING MECHANI SM Filedsept; 4,. 1936 2 Sh eets-Sheet 2' m U) T Q v I N a U E H L 3 M c/W004 Roy SGJy Ol'd/ Patented Fen-21.1939

PATENT *OFFICE 2.138.305 rnno'rrmcomonnme MECHANISM Roy S. Sanford, New York, N. Y., assignor to Bendix-Westinghouse Automotive Air Brake Company, Pittsburgh, Pa... a corporation of Delaware Application September 4, 1936, Serial No. 99,502

'1 Claims. This invention relates to speed-controlling mechanism and more particularly to mechanisms of this type especially adapted for internal'combustion engines.

Various systems have been proposed previously for controlling the speed of engines, and particularly those of the internal combustion type, 'in such a manner as to automatically maintain the speed of one or'a plurality of engines sub stantially constant regardless of changes in the load carried therebyj Many of these systems, however, have been complicated and costly due to the use of centrifugal governors .of various types driven by the engine, and have been further complicated by. mechanical linkage when adapted for operation from, a remote control station. v 1 It is, therefore, an object of the present invention to provide a novel and simple control system for an enginewhich will maintain a sub-.- stantially uniform engine speed under varying load conditions.

Another object 'is to provide a control system of the above type which may be readily adapted for controlling the speed remote point.

A further object is to provide a control system for a. plurality of engines so constituted as to automatically synchronize their speeds regardless of load variations, the synchronizing speed being selected by a single control member.

I The above and other objects will appear more fully from the following detailed description when taken in connection with the accompanying drawings illustrating one form of the invention. It is to be expressly understood, however, that the drawings are utilized for purposes of illustration only; and are-not intended to constitute a,

definition of the limits of the invention, reference being had for this purpose to the appended claims.

In the drawings, wherein similar reference characters refer to different views:.

Fig. 1 is a diagrammatic view, partially in section, of an engine and control system therefor constructed in accordance with the principles of the present invention, and Fig. 2 is a diagrammatic view of a similar syssimilar parts throughout the tem operable to control the speed of a pluralityof engines. v v

Referring more particularly to Fig. 1, in which isshown an engine 5,-preferably of the internal combustion type, having an intake manifold l, a throttle valve 8 and a. throttle-operating memof an engine frbm aias embodying in general a fluid pressure reservoir I 0, a throttle control mechanism II, and a control valve device l2, the latter being connected to the reservoir III by a conduit I3 and to the control mechanism II through a conduit I l.

It is well known that when engines are operated undervarying loads, constant manipulation of the throttle valve by the operator is necessary to maintain the engine speed constant under such conditions, and in an internal combustion engine of the type which draws an explosive mixture of fuel and air through its intake manifold past a throttle valve, the pressure in the intake manifold between the throttle valve and the motor tends to vary'appreciably in response to either a change in engine speed or a change in the throttlevvalve setting. For example, consider an engine operating under constant speed and load with the throttle half open. Under this condition, there will be a substantially constant vac- -uum in the intake manifold. If we now increase the load on the engine, it will tend tov slow down, with a consequent rise in pressure in the manifold, since the capacity of the engine as a vacuum pump is decreased. If the throttle is now opened wider, the engine can draw in more fuel and maintain its former speed and pumping capacity under the increased load, but it"will be readily apparent that with the increased throttle opening, it will be unable to maintain the degree of vacuum iormerly obtained in the intake maul-'- fold, it being well known that at constant engine speed, the intake manifold pressure is a function of the throttle valve opening, the pressure in-, creasing as the throttle is opened and decreasing as the throttle is closed. By. the present invention, novel means are provided for substantially eliminating the necessity for constant manipulation of the throttle valve by the operator, and

body member l5 having a cylinder bore l6 and a piston II slidably mounted therein and connected to the throttle-operating member Oby means of a piston rod lg and a pivotallyaconnected rod. l9.

The bore I8 is divided by the piston |'I into a pres- 8 by the piston I! may be properly controlled,

sure chamber 20 and an atmospheric chamber 2|, the former having a port 28a and the latter being connected to atmosphere through aport 22 5 in a cylinder bo're cover 23, the cover acting as a guide for the piston rod l8. The left end of the cylinder bore has an end wall 24 bored to receive the piston rod l8, apiston rod sealing device 25 being mounted within the bore, for sealing the 10 said rod. The left end of piston rod I8 is suitably connected to a diaphragm 28, which when clamped at its outer edge between the flanged end of the body member I5 and a similarly flanged end cover 21 forms an atmospheric chamber 28 15 on the right side of the diaphragm communicating with the atmosphere by a port 28. The piston rod I8 is biased toward the left by a spring 80 interposed between the left face of the body member i5 and a flanged portion 3| on the piston 20 rod. The leftward bias on the piston rod is opposed by a relatively strong spring 82 interposed between a hollow contact member 83 suitably attached, mecnanicallyland electrically to the left end of rod l8 and an insulating washer 84a caras ried by a second contactmember 34 attached by means of insulating washers 85 and 38 to a cover ,81, the latter being connected to cover member 21 through a hollow sleeve 88 to form a chamber 38 on the left side of the diaphragm 28. A port 40 80 is provided in the wall of the chamber and the latter is connected to the intake manifold I of the engine 8 as by means of a connector 4| and a conduit 42. It will be evident from the foregoing description that a novel throttle valve-controlling 85 mechanism has been provided, wherein a diaphragm responsive to intake manifold pressure is operatively connected with the throttle valve, while a piston responsive to pressure from another a source is also connected to the throttle and adapted for actuation thereof, the throttle being normally maintained in closed position by means of springs 80 and 82. It is pointed out that the springs 88 and 82 are so constituted as to normally maintain the contact members "and 84 in non-contacting relationship as shown, for reasons variable eifective area which increases as the throttle valve is opened wider, and due to the I relatively low vacuum existing in the intake manton further to the left, causingthe intake valve ifold for large throttle valve openings, it is sometimes desirable to have the control of the throtso tle valve by the diaphragm more sensitive under the above conditions. and use of the diaphragm arrangement described makes it possible to proportion and arrange the parts to obtain a throttle control that is adaptable to the particular as characteristics of a given engine. It is to be acterlsticsand operate under different nd? tions, and it is further'pbinted/out matur invention herein described may be to meetsuch charactertistics and-conditions.

a reservoir or source of fluid pressure l0 and a control valve i2 have been provided and, as previously described, the control valve receives air from the reservoir l0 through conduit I8 and is connected to piston chamber 28 by means of conduit l4 and port 20a. The control valve, as illustrated, is of the well known self-lapping type and is preferably constructed in a manner similar to that shown in the application of R. S. Sanford, Serial No. 88,889, filed in the United States Patent Office on July 3, 1936. The valve l2 of this type is shown as comprising a body member 48 adapted to slidably receive a piston member 44 in a hollow bore 45 to form a chamber 48 on the left side thereof, said chamber being closed at the left end by an air intake valve member 41, the latter being normally urged to closed position against an intake valve seat 48 by a spring 48. An exhaust valve portion 50 formed at the right end of the valve member 41 is adapted on movement of the piston to the left to engage a seat formed on the piston and close oil an exhaust port 52 in the piston. It will be readily apparent from the foregoing description that further movement of the piston to the left will open the intake valve 41 and admit fluid from reservoir III to chamber 48 through the conduit l8 and the open valve 41, and it will be further noted that if the piston is moved slightly to the right, it can assume a position such that valves 41 and 50 are closed and no fluid can enter or leave the chamber past the valves, the only other outlet from chamber 48 being through a port 58 in the wall of the chamber.- A cover 54 having a valve mounting bracket portion 55 and a control member bracket portion 58 carries a control member-51 pivotally mounted on the portion '58 by a pin 58 and adapted to actuate a hollow plunger 58 slidably mounted in the cover 54. Thecover and the plunger act as a closure-forv the cylinder bore 45 and form, in connection" with the piston 44,,an exhaust chamber 58a having an exhaust port '88 connecting it to atmosphere, the chamber'being connected to the piston exhaust port 52 by passages 52a. Interposed between the piston44 and the plunger 58v is a graduating spring 8|, said plunger and spring acting as a connecting means between the piston 44 and the control member 51. It will be evident from the above description that .a slight clockwise movement ofcontrol member 51 about pivot 58 will act through the sleeve 58 and spring 8| to move piston to the left to a point where seat 5| engages ex; haust valve 50, and that further clockwise movement of the control member will move the pis- 41 to open and admit air from the reservoir I to chamber 48 of the valve. If the control member is now held stationary, the intake valve will be hld open 'until the pressure acting on the left side of the piston is sumcient to overcome,

sition and will maintain a pressure in the cham-' ber 48 corresponding. to the degree to which the graduating spring is compressed ingly increase or decrease the pressure in chamy movement 'of the control member. Further compression 1 or decompression of the spring will correspond- In order that actuationof the throttle valve 1 auaaos ber 44, and in-like manner any change of pressure in the chamber due'to leakage will unbalance the .pressures on the piston, causing the latter; to actuate the valves to compensate for the change. From the foregoing, it will be evident that two separate control means are provided for the throttle valve, one such means including the diaphragm 26 and being adapted to actuate the throttle through rods l8 and I9 -'and lever 9 in response to pressures in intake manifold 'l transmitted to the diaphragm 26 through conduit 42, and the other including piston I1 operatively connected to the throttle through rods l8 and I9 andlever 9 and being controlled by the valve II, which as described is so constituted as to estab-. lish and maintain a predetermined pressure in piston chamber inaccordance with the position of control member 51 as determined by the operator. For example, if it is desired to run the motor at half open throttle, the operator moves the control member 51 in a clockwise direction to admit a predetermined pressure to chamber 20. Piston I! will thereupon be moved to the right to open the throttle valve. With the engine running, the piston .l'l has to overcome the force of springllll and also the force exerted by manifold vacuum on diaphragm 26, and the control member 51 may be set in such a position I that the above forces wilL balcance at. a point where'the throttle is half open, and if the motor is carrying a constant load, the above forces will continue tobe balanced. If the load is now decreased, the engine will immediately tend to speed up, resulting in a higher vacuum in the intake manifold. This change in vacuum will immediately unbalance the forces acting on the throttle, the higher vacuum acting on diaphragm 28 to move it to the left and close the throttle,

.thus tending to prevent racing of the engirfe and maintain its speed constant. In the same manner, an increase in load will tend to lessen the engine speed with a resultant decrease in intake manifold vacuum, and the consequent decrease in force exerted by the diaphragm 29 on the throttle valve rod I8 will allow piston I] to open the throttle wider, thus holding the engine speed constant under the higher load. It is to be pointed out that during the above action. the 'pressure acting on the throttle-actuating piston I! is constant for a given setting of the control memberl'l, apy change of pressure in the chamber 20 due to movement of the piston I] in response to variations in intake manifold vacuum being immediately compensated for by the self-lapping action of the control valve l2 as hereinbefore described. It will thus be seen that novel, ef-

ficient and simple means have been providedwhereby a given engine speed may be selected and maintained under varying loads through the setting of a single remotely-situated control member by the operator.

"In order that the operator or other persons may be advised when=the throttle is closed to idling position, see Fig. 1, electrical contacts 33 and 34 have been provided, and as previously described, when the engine is inoperative and chambers 20 and" are at atmospheric pressure, the contacts to for easy starting. As soon as the engine starts,

however, a high vacuum is built up in the intake manifold,- and this vacuum actingon the diawire 84, contact 33 being'grounded to the engine or frame through piston rod l8, housing I! and a connection65, and contact 34 being connected to the battery by a wire '66, it being evident thatwith the indicator 63 grounded through a wire 61, closure of the contacts 33 and 34 will complete the circuit and by the consequent operation of the indicator 83 advise the operator or other interested persons that the throttle is set in idling position with the engine running. It. is pointed out in this connection that with the control member 51 in'off position, stoppage of the engine will allow spring 32 to open the contacts, and under these conditions, inoperativeness of the indicator will advise the operator that the engine has stopped.

It will be apparent to those familiar with the operation of engines that it is often desirable to synchronize the speeds of a plurality of similar engines operating under varying loads, preferably keeping all the engines under control of one operator. It will be readily understood by those skilled in the art that the engine control system hereinbefore described is particularly adapted to this type of control. Referring particularly to Fig. 2, wherein are illustrated a pair of engines 6 having individual intake manifolds l and associated throttle valves, not shown, adapted to be operated through levers 9, separate throttle control mechanisms ii are attached to separate engines as by means of brackets 6t, and operatively connected to throttle levers 9 by rods l8 and [9. It will be understood that throttle control mechanisms HI are constructed in a manner similar to the mechanism illustrated in Fig. l, and that a common control valve l2 supplies air under pressure to piston chambers 20 in the mechanisms through conduit I l and branch conduits 69 and I0, the control valve receiving its air supply from a fluid pressure source l0 through conduit l3, as heretofore set forth. In like manner each actuating mechanism has its chamber 34 connected to a corresponding engine manifold I through conduits 42, and there is thus provided for each engine a throttle valve control mechanism including throttle-actuating means responsive to the pressure of the intake manifold of the engine and a second throttle actuator responsive to pressure supplied by the single control valve l2. From the above, it will be seen that for-a given engine load condition, the operator may set the control member 51 to select a predetermined engine speed, and that thereafter variations in load on each engine will cause corresponding variations in intake manifold pressures and that the vacuum-operated portions of the throttle valve control mechanisms will thereafter automatically vary the throttle valve openings on the engines to maintain their speeds sub..

stantially synchronous.

" While oneembodiment of the invention has been described in considerable detail, it will b understood by those skilled in the art that other forms and-applications of the invention'may be readily used without departing from the spirit of the invention- Reference will, therefore, be had to the appended claims for a definition of the limitations of the invention.

,,What is claimed is:

control valve associated therewith for setting and controlling the pressure in said motor, resilient,

means i'or biasing thethrottle toward closed po- 19 sition, a throttle valve actuator responsive to intake manifold pressure. for varying the position of said throttle means independently of the setting 01' said control valve and means for over- .coming said resilient means and holding the throttle valve in partially openedposition when the engine is stationary. 2. In a control system for engines of the type having an intake manifold and a throttle valve associated therewith, fluid pressure means ingo cluding a control device for establishing and maintaining a predetermined setting of the throttle valve, means responsive to intake manifold pressure for controlling said throttle valve setting independently-of said first named means and r 25 other means independent of said first named means for automatically opening the throttle valve when the engine stops.

3. In combination with a throttle control system for an engine having an inlet passage and n a throttle valvaassociated therewith, a throttle v valve control element, a source of fluid pressure, a fluid motor for urging said element toward throttle opening position, means including a control valve operable at a predetermined setting a thereof to"establish and automatically maintain a corresponding pressure in said motor and 'means including a pressure responsive member connected to said element having an effective area variable with the degree of movement i andresponsive' to variations in inlet passage pressure for urging said element toward throttle closing position.

2,14s,aos

4. In a control system for an engine of the type having an intake manifold and a throttle valve associated therewith, fluid pressure means including a control device for establishing and maintaining a predetermined setting of the throt- 5 tie valve, and means responsive to intake manifold pressure and including a pressure responsi've member having an effective area variable with movement thereof for controlling said throttle valve setting independently of said first named means.

5. A control system for an engine of the type having an inlet passage and a throttle valve associated therewith comprising throttle valve actuating means and control means therefor, means for biasing said throttle toward open, position when the engine is stationary, and means including a member responsive to inlet passage pres-- sure for opposing the-action o1 said biasing means and urging said throttle toward closed position on starting of the engine. 7

6. A control system for an engine of the type having an inlet passage and a throttle valve associated therewith, comprising throttle valve actuating means and control means therefor, means 25 including a member responsive to inlet passage pressure for urging the throttle toward closed position, and means effective on an increase of pressure in said passage for partially opening said throttle valve.

7. In a control system for an engine of the type having an inlet passage and a throttle valve associated therewith, means including a member responsive to inlet passage pressure for biasing and moving said valve toward closed position, a fluid actuator for biasing and moving said throttle valve toward open position, and self-lapping control valve means operable for establishing and maintaining a predetermined pressure in said ac-s tuator regardless of the action of said first named a means.

S. SANFORD. 

